About the case where "Docker" freeter tried to put Docker in the existing Rails application

Hello

Rumor has it that modern development companies are definitely adopting this time.

Docker

I would like to introduce how to introduce (70% of memo elements for yourself)

First of all, I would like to explain about Docker. I've only dealt with Docker once, so what I'm talking about is To get acquainted with Docker, I recommend this article I will explain what Docker is like very carefully.

Find out about servers and the history of Docker's use.

First of all Create a dockerfile and use this kanji


FROM ruby:2.6　//Version specification command ruby-Confirm with v

RUN apt-get update -qq && \
    apt-get install -y build-essential \ 
                       libpq-dev \        
                       nodejs      

RUN mkdir /Books app name

ENV APP_ROOT /Books 
WORKDIR $APP_ROOT

ADD ./Gemfile $APP_ROOT/Gemfile
ADD ./Gemfile.lock $APP_ROOT/Gemfile.lock

RUN gem install bundler 
RUN bundle install
ADD . $APP_ROOT

`webpacker.yml`



default: &default
  source_path: app/javascript
  source_entry_path: packs
  public_root_path: public
  public_output_path: packs
  cache_path: tmp/cache/webpacker
  check_yarn_integrity: false  //*Caution
  webpack_compile_output: true

  # Additional paths webpack should lookup modules
  # ['app/assets', 'engine/foo/app/assets']
  resolved_paths: []

  # Reload manifest.json on all requests so we reload latest compiled packs
  cache_manifest: false

  # Extract and emit a css file
  extract_css: false

  static_assets_extensions:
    - .jpg
    - .jpeg
    - .png
    - .gif
    - .tiff
    - .ico
    - .svg
    - .eot
    - .otf
    - .ttf
    - .woff
    - .woff2

  extensions:
    - .mjs
    - .js
    - .sass
    - .scss
    - .css
    - .module.sass
    - .module.scss
    - .module.css
    - .png
    - .svg
    - .gif
    - .jpeg
    - .jpg

development:
  <<: *default
  compile: true

  # Verifies that correct packages and versions are installed by inspecting package.json, yarn.lock, and node_modules
  check_yarn_integrity: false  //*Caution

  # Reference: https://webpack.js.org/configuration/dev-server/
  dev_server:
    https: false
    host: localhost
    port: 3035
    public: localhost:3035
    hmr: false
    # Inline should be set to true if using HMR
    inline: true
    overlay: true
    compress: true
    disable_host_check: true
    use_local_ip: false
    quiet: false
    pretty: false
    headers:
      'Access-Control-Allow-Origin': '*'
    watch_options:
      ignored: '**/node_modules/**'


test:
  <<: *default
  compile: true

  # Compile test packs to a separate directory
  public_output_path: packs-test

production:
  <<: *default

  # Production depends on precompilation of packs prior to booting for performance.
  compile: false

  # Extract and emit a css file
  extract_css: true

  # Cache manifest.json for performance
  cache_manifest: true

`database.yml`


default: &default
  adapter: mysql2
  encoding: utf8
  pool: <%= ENV.fetch("RAILS_MAX_THREADS") { 5 } %>
  username: root　　
  password: example
  # socket: /tmp/mysql.sock

  host: db

development:
  <<: *default
  database: Books_development Your own database name (same below)

test:
  <<: *default
  database: Books_test

production:
  <<: *default
  database: Books_production
  username: Books
  password: <%= ENV['BOOKS_DATABASE_PASSWORD'] %>
  username: root
  password: <%= ENV['DATABASE_PASSWORD'] %>
  socket: /var/lib/mysql/mysql.sock

`docker-compose.yml`



version: '3'
services:
  db:
    command: --default-authentication-plugin=mysql_native_password
    restart: always
    environment:
      MYSQL_ROOT_PASSWORD: example  //In my case, I didn't set it, so I decided to use it.
    image: mysql
    ports:
      - "4306:3306"

  web:
    build: .
    command: bash -c "rm -f tmp/pids/server.pid && bundle exec rails s -p 3000 -b '0.0.0.0'"
    volumes:
      - .:/Books
    ports:
      - "3000:3000"
    depends_on:
      - db

The caution mark will be introduced at the end.

After writing,

% docker-compose build

Wait for a while while drinking a lot of milk and coffee milk.

If I can

% docker-compose run web bundle exec rake db:create

% docker-compose run web bundle exec rake db:migrate

If you can do it without problems

% docker-compose up

Launch the container to finish.

the end.

Finally, I would like to introduce some errors that appear as usual when launching.

web_1  | => Booting Puma
web_1  | => Rails 6.0.3.2 application starting in development 
web_1  | => Run `rails server --help` for more startup options
web_1  | sh: 1: yarn: not found
web_1  | 
web_1  | 
web_1  | ========================================
web_1  |   Your Yarn packages are out of date!
web_1  |   Please run `yarn install --check-files` to update.
web_1  | ========================================
web_1  | 
web_1  | 
web_1  | To disable this check, please change `check_yarn_integrity`
web_1  | to `false` in your webpacker config file (config/webpacker.yml).
web_1  | 
web_1  | 
web_1  | 
web_1  | 
web_1  | 
web_1  | Exiting
books_web_1 exited with code 1

As you can see if you read this error calm down,

% yarn install --check-files
or 
% yarn update

I introduced it earlier.

Make sure that the caution mark is false (It seems that the description will check if the JavaScript package is the latest, but I don't need it now, so set it to false.)

I think that if you do these things, it will be cured.

I'm a complete beginner, so I'm going to study Docker again.

This time

that's all.

Reference article (Rather almost the same) [Introduce Docker with MySQL to the existing rails6 app. ](Https://qiita.com/momokan928/items/d560fff3855fcbe0b811#1dockerfiledocker-composeyml%E3%82%92%E6%97%A2%E5%AD%98%E3%82%A2%E3%83%97% E3% 83% AA% E3% 81% AE% E3% 83% AB% E3% 83% BC% E3% 83% 88% E3% 83% 87% E3% 82% A3% E3% 83% AC% E3% 82% AF% E3% 83% 88% E3% 83% AA% E3% 81% AB% E4% BD% 9C% E6% 88% 90% E3% 81% 99% E3% 82% 8B) Introduction to Docker